Table 3

Unweighted regression coefficients from OLS regression models predicting sleep duration (min) in 2010, NLSY97†

	Full sample (n=4714)			Subsample (n=4459)
	Model 1 b (SE)	Model 2 b (SE)	Model 3 b (SE)	Model 1 b (SE)	Model 2 b (SE)	Model 3 b (SE)
Race/ethnicity
Non-Hispanic Black	−21.5 (3.2)*	−21.3 (3.2)*	−21.0 (3.2)*	−22.3 (3.2)*	−22.1 (3.2)*	−24.6 (3.5)*
Latino	−7.5 (3.4)*	−7.7 (3.4)*	−7.7 (3.4)*	−8.5 (3.4)*	−8.5 (3.4)*	−9.4 (3.9)*
Other	−22.1 (5.8)*	−22.0 (5.8)*	−22.2 (5.8)*	−22.4 (5.8)*	−22.3 (5.8)*	−21.5 (6.5)*
Degree attained by 2010
<Bachelor's degree	−9.1 (3.2)*	−10.0 (3.2)*	−9.9 (3.2)*	−6.9 (3.2)*	−7.8 (3.3)*	−7.6 (3.3)*
Number of hours worked (2010)
1–39	4.8 (2.7)	4.8 (2.7)	4.8 (2.7)	5.8 (2.7)*	5.7 (2.7)*	5.7 (2.7)*
0	−2.2 (7.3)	−2.0 (7.3)	−2.3 (7.3)	−5.3 (7.5)	−5.6 (7.5)	−6.2 (7.5)
Household income (2010)
0–49th centile	6.3 (3.1)*	6.1 (3.1)*	6.1 (3.1)	5.2 (3.1)	5.2 (3.1)	5.1 (3.1)
50–74th centile	2.7 (3.5)	2.7 (3.5)	2.6 (3.5)	1.8 (3.4)	1.8 (3.4)	1.6 (3.4)
Parents’ net worth (1997)‡
Negative	−10.9 (6.2)	−9.9 (6.2)	−10.5 (6.2)	−13.5 (6.1)*	−12.9 (6.2)*	−13.3 (6.2)*
Low	−10.0 (4.2)*	−9.0 (4.3)*	−9.6 (4.3)*	−11.2 (4.3)*	−10.6 (4.3)*	−11.1 (4.3)*
Middle	−8.7 (3.5)*	−7.8 (3.5)*	−8.2 (3.5)*	−9.2 (3.5)*	−8.6 (3.5)*	−9.0 (3.5)*
Any other financial debt at 25	−7.9 (2.6)*	−7.5 (2.6)*	−7.3 (2.6)*	−8.1 (2.6)*	−7.9 (2.6)*	−8.1 (2.6)*
Student loans by 2010§		−1.9 (0.8)*	−0.4 (1.1)
Student debt at 25					−0.5 (0.9)	0.4 (1.1)
Student debt at 25 squared					−0.02 (0.1)	−0.1 (0.1)
Interactions
Student loans×non-Hispanic Black			−5.4 (1.9)*
Student loans×Latino			−2.3 (2.2)
Student loans×Other			2.0 (3.6)
Student debt×non-Hispanic Black						−3.8 (1.9)*
Student debt×Latino						−1.6 (2.3)
Student debt×Other						4.1 (3.8)
Student debt squared×non-Hispanic Black						0.4 (0.2)*
Student debt squared×Latino						0.2 (0.2)
Student debt-squared×Other						−0.2 (0.4)
Intercept	408.8 (2.2)*	409.2 (2.2)*	409.1 (2.2)*	416.0 (6.2)*	416.5 (6.3)*	417.2 (6.3)*
F-test	9.2*	9.1*	8.7*	9.5*	9.0*	7.9*

*p≤0.05, two-sided test.
†All models adjust for gender, nativity, age (2010), self-rated health (1997), enrolment history, region (2010), urban residence (2010), marital status (2010), number of children (2010), occupation (2010), total jobs held (2010) and year of last enrolment. The subsample also adjusts for the year respondents reported on debt.
‡Low, ∼5th to 24th centile; Middle, 25th to the 74th centile; Top, 75th centile and higher.
§Student loans and student debt centred at their grand mean and divided by 5000.
All covariates centred at their grand mean, except for race/ethnicity, which was not centred. Year of last enrolment and year respondents reported on debt were centred at 2010.
Reference categories: non-Hispanic white, Bachelor's degree or higher, working 40 h or more, household income at 75th centile or higher, parental wealth at 75th centile or higher.
NLSY97, National Longitudinal Survey of Youth 1997.